Field of the Invention
The present invention refers to surgical instruments in general, and more specifically to a new constructive arrangement provided in a surgical instrument particularly suitable for use in surgeries wherein the insertion and/or removal of non-solid substances is required.
Inserting and/or removing non-solid substances from the human body is a widely known surgical technique used by surgeons in different fields of surgery for several different purposes. Such purposes range from the injection of medicinal cements in orthopedic surgeries for speeding up the recovery of a fracture, or silicone in plastic surgeries, to the removal of fats and other liquid secretions.
As it is widely known by those skilled in such surgical arts, typically the commercially avaliable non-solid substances to be inserted into the human body are packed in the form of syringes or squirts, by means of which the product may be injected into the desired places.
The greatest problem of using said non-solid substances however, lies in the injection application of the product.
Actually, the characteristics of some of said products, such as high density and low fluidity besides the size and weight of these syringes and squirts, prevent them from being used as conventional injection syringes.
Therefore, generally, the injection of such non-solid substances involves the use of special surgical instruments commonly known as pistols or guns.
Typically, these guns comprise a housing for receiving the syringe or squirt containing non-solid substances and an alternative triggering system which actuates a plunger in order to force the non-solid substances to leave the syringes or squirts and penetrate into the human body.
However, the use of such guns for injecting non-solid substances poses some problems which need to be solved so that the same may be further used.
One primary and serious drawback of such guns is directly related to the alternative triggering mechanism used for actuating the plunger that forces the non-solid substances to leave the squirt.
In effect, the use of an alternative triggering mechanism for actuating the plunger involves an intermitent movement of the plunger, that is, step by step. Therefore, as a consequence, the application of non-solid substances shall be prone to interruptions in its continuity which, besides providing an uneven application of the product, may even jeopardize the final result of the surgery in some situations.
For example, when a gun is used for injecting medicinal cement in an orthopedic surgery, the intermitent movement of the plunger allows for the formation of air bubbles within the cement being applied, which seriously jeopardize the stability of the consolidation desired.
Another drawback of these guns for injecting non-solid substances is the relatively heavy weight of the gun with the syringe or squirt mounted thereon, which makes its use difficult since any little disbalance may impair a precise application of the non-solid substance.
Additionally, since these guns are manufactured from disposable materials such as non-sterilizable plastic materials they may only be used once, which raises the cost of every surgery.